405 



tion on certain intermediate food-plants may be affected by the nature 

 of the preceding one ; this question, however, requires further 

 investigation with reference to the factors concerned, especially the 

 condition of the food-plant and temperature. Other factors influencing 

 the constitution of the cell sap of plants are climate, soil conditions, 

 agricultural methods, and manurial treatment. It is also probable 

 that the wide range of variation in numbers on different varieties of 

 plants is also largely due to the variable fertility of the agamic females. 

 The greatest reproduction occurs with the early viviparous generations ; 

 thus there would appear to be some relation between the time of the 

 year and the degree of infestation. 



Morrill (A. W.). Report of the Entomologist. — 10th Ann. Rept. 

 Arizona Commiss. Agric. & Hortic. W17-18, Phoenix, 1919, 

 pp. 29-73, lv3 iigs , 2 plates, 7 tables. [Received 21st June 1921.] 



The area under cultivation in Arizona during 1917 was largely 

 increased, and accordingly pest control became more important. At 

 tlie present time the alfalfa weevil [Hypera variabilis], the pink boll- 

 W'orm [Platyedra gossypieUa], and the cotton boll weevil [Anthonovius 

 grandis] are the greatest insect menaces. 



The usual inspection was made of orchards and nurseries for the 

 location and eradication of pests. Spraying operations were continued 

 against the codling moth [Cydia pomonella] and the San Jose scale 

 [ Aspidiotus perniciosus]. 



Control measures were adopted against grasshoppers infesting 

 lucerne, and one species, Eucoptolophus subgracilis, Caudell, caused 

 severe damage to vegetables. Tests with grasshopper baits were 

 continued during 1917 and 1918, on cotton and lucerne fields, against 

 Melanoplus differentialis. A combination of half and half wheat 

 bran and pine sawdust was found equal to and easier to distribute than 

 wheat bran only, while sawdust alone is definitely inferior. Barley 

 middlings give fairly good results when substituted for wheat bran. 

 As ingredients in poisoned baits, molasses, especially the darker grade, 

 are unnecessary, and if used with citrus fruits reduce the effectiveness 

 of the bait. Cantaloups and oranges are superior to lemons, and the 

 former are cheaper. London purple is inferior to Paris green. Dry horse 

 manure as a substitute for wheat bran is only recommended for use 

 in emergencies. 



The principal means of destroying cutworms are poisoned baits, 

 and the usual grasshopper bait is generally recommended. It can be 

 assumed that lemons and molasses are of no value in these baits. In 

 the autumn of 1918, excellent results were obtained against Feltia 

 annexa, Tr., by using the bran, Paris green and water combination. 



Experiments were carried out in 1918 for the control of Lvgiis 

 elisus var. hesperus, Knight, and L. pralensis ohlineatus, Say (cotton- 

 square daubers). At present remedial measures cost more than the 

 slight damage the bugs cause to crops. It was found that lucerne 

 fields heavily infested with these pests seriously menace neighbouring 

 cotton fields. Lucerne fields should be cut so that these bugs, as well 

 as grasshoppers, are concentrated in the centre, which should be left 

 uncut. They can then be collected by means of a hopperdozer. 



The peach-twig borer [Anarsia lineatella] is the most troublesome 

 peach insect. The eastern peach-tree borer [Aegeria exitiosa], 

 previously only recorded near Prescott, has now been reported at 

 Payson. Frankliniella morilli, Morg. (apricot thrips) only caused 



